USING A MAGNET to pick up wire and other metal objects from grassland prior to mowing or grazing has helped reduce the risk of wire damage in one Somerset herd.

Silage for Michael Eavis” 350 Holsteins is made from 162ha (400 acres) which play host to the Glastonbury music festival. Fed up with collecting scores of tent pegs and bottle tops months after the event and concerned about wire being eaten by cows, Mr Eavis had local engineers make a 5m wide magnet.

This is mounted on a stainless steel skirt set above a tray and attaches to the front of a tractor. “We put the harrows on the back so it”s a one-pass operation and go over fields three times a year,” he says.

“The magnet attracts all metal objects to the steel skirt. When it”s removed, everything falls into the tray below. We then put the metal into a skip and sell it as scrap.”

The farm”s vet Paddy Gordon, of Shepton Vet Group, says there has been a focus on worn clamp tyres, but producers should also be aware of other sources of wire.

“Wire can appear in straights. Nails are discarded in fields, or bits of fencing wire get chopped up by the mower. We”ve found all of this when doing post-mortems or surgery on cows,” he says.

Herds which have a problem can blanket treat cows with a magnetic bolus. However, Mr Gordon says the alternative is to reduce the risk of cows picking up wire.

This includes regularly monitoring tyres on the clamp, discarding perished ones and fitting a magnet to the diet feeder chute. “Mr Eavis has found another option of passing a magnet over fields before silage making,” he says.

An added bonus for Mr Eavis has been improved work rates at silaging. The farm”s contractor John Davis reports a difference in fields cleared by the magnet. “Before, we would have up to 30 stops in a field, when we”d have to get out and look for the object,” he says.

“Metal detectors fitted on the forage harvester are sensitive enough to pick up a paper clip and they stop the machine to prevent metal entering the feed rollers. It holds us up when we want to get in and out as quickly as possible.”